Journal of Experimental Food Chemistry

It is well documented that blueberry phenolic compositions, such as phenolic acids and flavonoids differ based on species and cultivars. However, phenolic compositions in Florida blueberries have been little explored. Information on Florida blueberries are of interest as they are harvested earlier than other areas of the United States, which may result in compositional differences due to shorter daylight hours and cooler temperatures. Samples were harvested from University of Florida grower-cooperator farm near Gainesville, FL. After liquid-liquid extraction and C-18 SPE cartridge purification, concentrations of phenolic acids and flavonoids of twenty two blueberry cultivars (20 highbush and 2 rabbiteye) were measured using HPLC. Five phenolic acids (gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid and ferulic acid), two flavan-3-ols (catechin and epicatechin) and five flavonols (quercetin-3-galactoside or quercetin-3-glucoside, quercetin-3-arabinoside, myricetin, quercetin and kaempferol) were identified and quantified. Chlorogenic acid was the major component in highbush blueberries. Flavonoid and phenolic acid composition were profoundly different among Florida blueberries and these differences have not been previously reported. The first two components of PCA explained 95% of the variation totally; it showed clear differentiation of blueberry cultivars based on phenolic composition. The majority of the variation between the cultivars was due to variation in quercetin-3-galactoside or glucoside, quercetin-3-arabinoside and chlorogenic acid, which are most likely due to genetic and maturity differences. Complete-linkage clustering analysis displayed five significantly different (p<0.05) clusters of blueberries, which were in agreement with PCA results, although some small differences were noted. Furthermore, Florida blueberries can be differentiated based on phenolic composition between highbush and rabbiteye species and varieties. Low flavanol content in rabbiteye blueberries may be related to maturity as these compounds typically decrease as berries ripen. Although the concentrations for phenolic compositions were lower than found in other reports, Florida blueberries contained a greater range of phenolic compounds. This information is valuable for blueberry breeding programs and growers for development of higher phenolic composition cultivar.

The use of chitosan acid salts was assessed in the clarification orange nectar. Clarification process was performed at laboratory scale by the classical methodology of jar test by adding chitosan acetate or chitosan lactate at concentrations between 0 g/L and 2 g/L of nectar. Numerical optimization method was used through an IV Optimal response surface for the best variant of coagulation-flocculation based on clarification yield. No significant effect of the salt type and concentration or clarification time on the physicochemical parameters of nectars were observed. Both chitosan acid salts could be used as clarifying agents, although chitosan lactate at 1 g/L was more effective, obtaining the highest yield (66.14%) to a time of 90 min. In general, there was no significant influence of the type and concentration of chitosan acid salt on the sensory attributes of the products and nectar clarified with chitosan lactate showed the higher overall quality.

Objective: A study aimed at the validation of a high performance liquid chromatography (HPLC) method for detection and quantification of ivermectin (IVM) in commercial milk. Method: After a liquid-liquid extraction with acetonitrile and hexane, a derivatization with a mixture of trifluoroacetic acid and trifluoroacetic anhydride was performed. Chromatography conditions were a C8 column, a fluorescent detector (Ex. 360; Em. 470 nm), a run time of 25 minutes and an isocratic elution at 30°C. The methodology was validated in terms of selectivity, linearity, precision, recovery, limit of quantification (LoQ), limit of detection (LoD), and robustness. Results: The method showed an adequate linearity and selectivity (r2=0.999) with an elution time of 13.909 minutes. However, the repeatability and intermediate precision showed RSD values above of 20% and recovery between 37 to 79%. The calculated LoD and LoQ were 2.50 and 5.00 ng/ml respectively. Robustness showed a significant variation on the analytical method with small changes in heating time during the derivatization and flow rate of chromatography system. Conclusion: The HPLC-fluorescence method showed results partially satisfactory and could be the used for IVM detection in commercial milk samples.

The fatty acid composition was determined in the cultivated edible mushroom Agaricus bisporus (white), and the wild medicinal mushrooms, Turkey-tail (Trametes versicolor), Artist Conk (Ganoderma applanatum) and Tinder Polypore (Fomes fomentarius). The most prominent fatty acids present in all of the species studied were palmitic (C16: 0), stearic (C18: 0), oleic (C18: 1), and linoleic acid (C18: 2n6). The amount of linoleic acid in the cultivated species ranged from 75.35 ± 1.54%; compared to 16.80 ± 1.54 to 30.30 ± 1.54% in the wild medicinal mushrooms. Unsaturated fatty acids were the most abundant in both the cultivated edible and the wild medicinal mushrooms studied, which varied from 79.74 ± 1.76 to 80.51 ± 1.75% and 58.35 ± 1.75 to 69.61 ± 1.75% respectively. The saturated fatty acid amounts ranged from 29.22 ± 1.73 to 41.65 ± 1.73% in the wild mushrooms and 19.49 ± 1.73 to 20.28 ± 1.73% in the cultivated mushrooms. Oleic acid was the most abundant fatty acid in the wild mushrooms and varied from 20.66 ± 0.87 to 37.21 ± 0.87%. The n-6: n-3 ratios were (ranged between 5.78 ± 7.38 to 28.45 ± 7.38% in cultivated edible compared to 16.19 ± 7.38 to 55.42 ± 9.03% in the wild medicinal mushrooms) generally higher than the recommended value of 2:1 or 3:1 in human diets.